First responders, the military and other commercial operations often store and use vehicles inside a static or fixed location or facility. For example, fire stations typically store vehicles in a garage or apparatus room of a fire station, and many times those vehicles are running on some occasions while inside the facility. Other examples of where vehicles are stored or operated inside a fixed location or facility include maintenance garages, airport hangers, police stations, loading facilities, shipping facilities, military facilities or any other setting where it is desirable at times to have a vehicle powered by an internal combustion engine or the like running even for short time periods in an enclosed area. The fixed location where the vehicles are stored may be augmented with various systems and devices ensuring optimal, efficient, and safe-handling, storage and maintenance of the vehicles in such an enclosed area.
Operation of vehicles generally results in the generation of exhaust gases and particulate matter such as soot, much of which may not be visible directly to the human eye. The majority of first responder and commercial vehicles in these facilities are diesel vehicles, which are known to produce particulate matter harmful to humans when reaching an excess of certain specified levels. If these vehicles are operated inside an enclosed facility, the exhaust gases and particulates in the air may quickly increase. Exhaust gases from many internal combustion engines may also contain carbon monoxide and hydrogen sulfide, which are gases harmful to humans even in low concentrations, as well as carbon dioxide in large quantities, which may displace the available oxygen in an enclosed area, reducing available oxygen for breathing which may lead to asphyxiation or death.
To reduce potential health and safety issues of operating vehicles in enclosed spaces for even short time periods, many fixed locations may be equipped with an exhaust ventilation system for removing exhaust fumes from running vehicles. Exhaust ventilation systems are configured to capture the exhaust gases from the vehicles and transport the gases and particulate matter outside the building, sometimes filtering the air to remove particulate matter before exhausting the captured gases outside the facility. The exhaust ventilation system may have a variety of configurations but almost all systems include an exhaust fan at the facility operationally coupled to a vehicle's exhaust system through various ducts and hoses. More specifically, various ventilation system manufacturers offer competitive solutions for implementing such exhaust ventilation systems which typically include at least one flexible exhaust capture hose, which attaches to or is positioned proximate to a vehicle's exhaust system and is coupled to a blower; a network of rigid or flexible ductwork extending between the at least one flexible exhaust capture hose and the blower; a control system which activates the blower and also typically provides overcurrent protection to the motor of the blower; and a remote control system that uses a vehicle-initiated signal to activate the system based on simple physical proximity of the vehicle to the building. In operation, the hoses attach or are coupled to the vehicle exhaust system to evacuate exhaust fumes and soot before they can enter the air of the facility to prevent toxic fumes, gas, or particulate matter buildup in the air. The vehicle's combustion gases and particulate matter are then pulled through the network of rigid or flexible ductwork by the blower and vented outside of the facility. Therefore, the exhaust ventilation system reduces occupational exposure to exhaust fumes for first responders and other workers in such facilities, particularly where long exposures may occur, such as the first responders living at the facility or workers or employees that are continually exposed to vehicle exhaust fumes in enclosed spaces. Toxic fumes, gases and airborne particulate matter have been implicated as occupational health risks. Many first responder, airport, military, and commercial vehicles are situated in a fixed location which is enclosed and the vehicles may be kept running for extended periods of time or before responding to a call or task due to various operational conditions. While these vehicles are running, the facility's exhaust ventilation systems allow humans to avoid exposure to vehicle exhaust particulates and gases which have known health risks.
These exhaust ventilation systems are typically configured to be operational in response to a stationary vehicle being situated within and running in the fixed location. Once the vehicle leaves the fixed location, the exhaust ventilation system ideally turns off automatically. In this way, the energy use of the exhaust ventilation system is minimized. In addition, many first responder garages, facilities, and enclosed spaces are climate controlled and leaving the exhaust ventilation system on for extended time periods, while not coupled to a vehicle, quickly removes the conditioned air in the facility, increasing operational costs of the facility.
One technique for ensuring that the exhaust ventilation systems are turned off when no longer necessary is the installation of a proximity transmitter device in each vehicle. The vehicle proximity transmitter device communicates wirelessly with a reception unit or receiver situated in the fixed facility and attached to a controller associated with the facility exhaust ventilation system. In response to the vehicle or set of vehicles being outside a predetermined range (or a range based on the capabilities of the wireless transmission), the controller may issue a command to shut down operation of the exhaust ventilation system. For example, in response to the vehicle being situated at a specific distance away from the fixed location that includes the exhaust ventilation system, the evacuation functionality may be disabled. In order to accomplish this, a communication unit (or receiver unit) associated with the exhaust ventilation system may be equipped with a polling function that listens to the first responder vehicle transmitters and based on a non-response, a signal may be generated to instigate a disabling of the evacuation function. The transmitter in the vehicle may also communicate, such as through lack of signal that the vehicle has been shut down and there is no longer any need for the exhaust ventilation system to be operational. One problem with this automatic control is if the human operators shut off the vehicle proximity transmitter, it could cause the system to not function when the vehicle enters the enclosed space.
Often times, a vehicle may still be within the wireless range of the exhaust ventilation system's communication unit, but not physically be within the confines of the fixed location. For example, many fire departments conduct training in the parking lot of the facility that stores the vehicles, well within proximity range of the communicator or receiver in the facility, but outside the facility. While some vendors recommend manually disconnecting the power leads to the proximity transmitter in the vehicle to prevent nuisance activation, that procedure may void the warranty of the exhaust ventilation system. Problems occur when a vehicle is hooked up or operationally coupled to the facility exhaust system and the vehicle is running but the evacuation function of the exhaust ventilation system is not active due to the proximity transmitter in the vehicle not being active. For example, not only may the hoses that attach the exhaust ventilation system to the tailpipe of the vehicle be damaged by the heat of the vehicle exhaust; carbon monoxide, toxic fumes and particulate matter may accumulate unnoticed to any incidental humans in the facility. Any vehicle running in an enclosed facility and not connected to an operating exhaust ventilation system creates a dangerous situation, particularly if the incidental humans in the facility believe the system is active. Therefore, prevailing wisdom in the industry is that the vehicle proximity transmitters in the vehicles should never be disabled, without a reliable mechanism to automatically re-enable the transmitter. Thus, the exhaust ventilation system in the facility commonly will still perform an evacuation function while the vehicle is outside the facility, within a set proximity and is running. In these situations, the exhaust ventilation system will not be disabled, and will continue operation even though it is not needed, thus, wasting energy associated with the operation of the exhaust ventilation system and adding unnecessary use of the exhaust ventilation system, when such system is not needed. In addition, when a vehicle equipped with a transmitter drives past a fixed location, it may cause the exhaust ventilation system or similar device to turn on in the facility, even though the vehicle has no desire to enter the fixed location or facility, and may not even be based at that location. Most current exhaust ventilation systems that have the ability to automatically turn off and on typically use a simple RF transmitter mounted in the vehicle communicating with a stationary receiver mounted in the building as the means of signaling the control panel to activate the exhaust system blower motor, and some systems use a coded transmitter to reduce false starts or nuisance activations. More specifically, while relatively low-cost and simple, the RF transmitters and receivers have a large and variable activation range, and can activate due to vehicles tens to hundreds of feet from the building, resulting in nuisance activations of the exhaust system. To reduce the nuisance activations, a transmitter encoding scheme is used to associate specific transmitters with specific receivers. For example, a fire department with two fire station buildings, each with an exhaust ventilation system, might elect to program the vehicle transmitters for each building with different codes. Thus, a vehicle normally used in a first station traveling past a second station within range of the RF receiver would not activate the exhaust system of the second station. Unfortunately, this creates a new and more problematic nuisance if a vehicle normally used in a first facility is temporarily relocated to a second facility. If the change is permanent, the transmitter modules could be manually swapped between vehicles or the systems could be reprogrammed to recognize different codes. However, for companies or environments with large numbers of buildings and vehicles, such manual swapping or reprogramming would be unacceptably tedious, time-consuming, and still could cause serious issues if the operators of the vehicle expect the system to automatically function and it does not operate. As such, one primary weakness of the present RF transmitter/receiver solution for automating the off and on cycling of exhaust ventilation systems is that the transmitters typically have a coverage range of thousands of square feet, making it not uncommon for a vehicle containing a transmitter to activate a building exhaust system receiver from over 500 feet away. This 500 foot radius is well within many areas where a vehicle will be operational, but not inside the facility, such as where outdoor training occurs for first responder vehicles.